Q400 question?

Captain X

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Just curious, how come the spoilers on the Q400 are deployed before you guys advance the power for takeoff?

I mean systems-wise...or is it an airline-specific procedure?

I noticed this in EWR the other day and it struck me as odd.
 

LowlyPropCapt

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Not a Q pilot, but I am dash driver and with the exception of the 200/300 (which don't have a ground mode for the roll spoilers) I think they all operate the same:

Conditions for roll spoiler in ground mode deployment are:

1. Wieght on all three gear
2. Flight/taxi sw. to flight (taxi retracts spoilers on ground)
3. Power levers near flight idle. (microswitch in power lever quadrant).

Crossing the holdshort line, the flight/taxi switch is moved to flight, so all three deployment criteria are met. As the power is increased above flight idle, the spoilers retract and begin to act like regular roll spoilers again.

A Q driver might tell you different, but that's how the -100 works.
 

rustypigeon

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"somebody tell that commuter pilot trying to take off that his spoilers are up!"
 

paulsalem

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What else does the flight/taxi switch control?

What would happen if you tried to take off with the switch in the taxi position?
 

jellynuts

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What else does the flight/taxi switch control?

What would happen if you tried to take off with the switch in the taxi position?

it automatically goes to flight when you hit a certain power lever angle. my solution to lazy captains!
 

kf4amu

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Some captains goose the power levers so it snaps to flight automatically...saves the FO the trouble of leaning over to flip it. Also activates the TO warning horn briefly if you arent configured correctly.
 

Snaab

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I fly the 400 and we put the Flight/Taxi (spoiler) switch to "Flight" when we taxi into-position-and-hold, and the spoilers (all 4) go 'up' as a self-test. They will stay in the 'up' position until we advance the power levers above a 12-degree power lever angle switch, then they're automatically stowed.
 

EatinRamen

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I'm guilty of saying on the tower freq "your spoilers are up" cause I didn't know better till just now.
 

rustypigeon

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I've heard some guys get real cocky when telling us our spoilers are up. Kind of like they were saving the day or something.
 

DYLIN

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I've heard some guys get real cocky when telling us our spoilers are up. Kind of like they were saving the day or something.
Not saying that I think it's cool that they sound cocky.

But -- I think it is very bizarre that the manufacturer designed it like this.
 

Salukipilot4590

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I fly the 400 and we put the Flight/Taxi (spoiler) switch to "Flight" when we taxi into-position-and-hold, and the spoilers (all 4) go 'up' as a self-test. They will stay in the 'up' position until we advance the power levers above a 12-degree power lever angle switch, then they're automatically stowed.
You should be in the training department. That was an excellent explanation!
 

Singlecoil

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Not saying that I think it's cool that they sound cocky.

But -- I think it is very bizarre that the manufacturer designed it like this.
They didn't. As previously stated, the switch automatically moves to flight as the power levers advance. The system was designed so that during ground ops, the spoilers stay down because the taxi switch is in taxi. As you advance the power levers on takeoff, the spoilers will still stay down because the power lever angle switch is tripped before the power levers automatically flip the taxi switch to flight.
I can't think of any reason why you would want to see if your spoilers all deploy in the ground mode before you takeoff. Are you going to land on an aircraft carrier? Is this a Dash-8 or an A-380? Why don't jet pilots check the ground mode operation of their spoilers prior to takeoff?
I guess you could argue that there is a manual lever to deploy the spoilers in a jet should the auto deploy fail, but do you ever absolutely need the spoiler to deploy in a Dash?
 

FirstMate

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I can't think of any reason why you would want to see if your spoilers all deploy in the ground mode before you takeoff. Are you going to land on an aircraft carrier? Is this a Dash-8 or an A-380? Why don't jet pilots check the ground mode operation of their spoilers prior to takeoff?
I guess you could argue that there is a manual lever to deploy the spoilers in a jet should the auto deploy fail, but do you ever absolutely need the spoiler to deploy in a Dash?
I wouldn't think of this as a 'spoiler check' when switching from 'taxi' to flight'...the actual check is when the f/o does a flight control surfaces check (the usual up, down, letf right, etc) while watching the boards go up and down on the control surfaces display and watching for any control surface lights to illuminate). Not to mention, there is a t/o warning horn that will make you jump if any of the boards are deployed.

Only had limited experience on unimproved short fields on the dash, but there are some good videos out there that show -100's landing on ~2000' gravel runways in Canada where every foot probably counts.
 

Quimby

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They didn't. As previously stated, the switch automatically moves to flight as the power levers advance. The system was designed so that during ground ops, the spoilers stay down because the taxi switch is in taxi. As you advance the power levers on takeoff, the spoilers will still stay down because the power lever angle switch is tripped before the power levers automatically flip the taxi switch to flight.
I can't think of any reason why you would want to see if your spoilers all deploy in the ground mode before you takeoff. Are you going to land on an aircraft carrier? Is this a Dash-8 or an A-380? Why don't jet pilots check the ground mode operation of their spoilers prior to takeoff?
I guess you could argue that there is a manual lever to deploy the spoilers in a jet should the auto deploy fail, but do you ever absolutely need the spoiler to deploy in a Dash?

Not a problem in a Dash 8-100/200, no hook required.:D
 
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